Review of low salinity waterflooding in carbonate rocks: mechanisms, investigation techniques, and future directions

Tetteh, Joel T.; Brady, Patrick V.; Ghahfarokhi, Reza Barati

doi:10.1016/j.cis.2020.102253

Cited by 115 publications

(73 citation statements)

References 220 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted that the observation of improved oil recovery in rocks occurs over a series of length and time scales. 5 , 43 , 44 Across the length scale, SCM serves to provide an understanding of the rock–brine–oil interactions at the nanoscale, where the rock surface is considered as a smooth colloidal particle interacting with oil molecules. This technique neglects the role of surface roughness, which has been studied to influence carbonate rock.…”

Section: Introductionmentioning

confidence: 99%

“…The observations at the nano and microscales also translate to the observation of oil recovery at the macroscale through coreflooding experiments. 5 , 54 However, the time it takes for oil to be recovered during low salinity waterflooding has seldomly been treated in the literature. In a recent work by Pourakaberian et al, 55 the wettability alteration process in porous media was observed to be slow due to the electro-diffusion of ions at the thin water film and its effect on the electrostatic forces.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ionic Interactions at the Crude Oil–Brine–Rock Interfaces Using Different Surface Complexation Models and DLVO Theory: Application to Carbonate Wettability

2022

Self Cite

View full text Add to dashboard Cite

The impact of ionic association with the carbonate surface and its influence toward carbonate wettability remains unclear and is an important topic of interest in the current literature. In this work, a triple layer model (TLM) approach was used to capture the electrokinetic interactions at both calcite–brine and oil–brine interfaces. The developed TLM was assembled against measured ζ-potential values from the literature, successfully capturing the trends and closely matching the ζ-potential magnitudes. The developed TLM was compared to a diffused layer model (DLM) presented in previous works, with the DLM showing a better match to the ζ-potential values for seawater brine solutions. The ζ-potential values predicted from both surface complexation models (SCMs) were used to calculate the total interaction energy (or potential) based on the Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory. It was observed that low Mg 2+ and high SO 4 2– concentrations in modified composition brine (MCB) made the calcite–brine interface more negative. However, at the oil–brine interface, low Mg 2+ made the oil–brine interface more negative but high SO 4 2– concentrations slightly shifted the oil–brine ζ-potential toward negative. At the crude oil–brine–rock (COBR) interfaces, low Mg 2+ and high SO 4 2– concentrations in the MCB were observed to generate a greater repulsive interaction energy, which could trigger carbonate wettability alteration toward water wetness. The absolute sum of the ζ-potential at both interfaces was observed to be correlated to the total interaction potential at a 0.25 nm separating distance. Thus, an increase in the absolute sum of the ζ-potentials would generate a greater repulsive interaction potential and trigger wettability alteration. Therefore, these SCMs can be applied to design modified composition brine capable of triggering a repulsive interaction energy to alter carbonate wettability toward water wetness.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ionic Interactions at the Crude Oil–Brine–Rock Interfaces Using Different Surface Complexation Models and DLVO Theory: Application to Carbonate Wettability

2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Despite considerable efforts to explain its origin and underlying mechanisms, pore-scale LSW processes remain poorly understood 28 . Until recently, numerous studies investigating wettability measurements at the core scale were conducted from which it was not possible to assert how the putative mechanisms are responsible for the low salinity effect (LSE) at the pore scale 28 , 29 . Therefore, addressing the connection between the low salinity-induced wettability changes and incremental oil recovery across different length scales is fundamental to further understand LSW as an EOR technique 29 .…”

Section: Introductionmentioning

confidence: 99%

Pore-scale imaging and analysis of low salinity waterflooding in a heterogeneous carbonate rock at reservoir conditions

Selem

Agenet

Gao

et al. 2021

Sci Rep

View full text Add to dashboard Cite

X-ray micro-tomography combined with a high-pressure high-temperature flow apparatus and advanced image analysis techniques were used to image and study fluid distribution, wetting states and oil recovery during low salinity waterflooding (LSW) in a complex carbonate rock at subsurface conditions. The sample, aged with crude oil, was flooded with low salinity brine with a series of increasing flow rates, eventually recovering 85% of the oil initially in place in the resolved porosity. The pore and throat occupancy analysis revealed a change in fluid distribution in the pore space for different injection rates. Low salinity brine initially invaded large pores, consistent with displacement in an oil-wet rock. However, as more brine was injected, a redistribution of fluids was observed; smaller pores and throats were invaded by brine and the displaced oil moved into larger pore elements. Furthermore, in situ contact angles and curvatures of oil–brine interfaces were measured to characterize wettability changes within the pore space and calculate capillary pressure. Contact angles, mean curvatures and capillary pressures all showed a shift from weakly oil-wet towards a mixed-wet state as more pore volumes of low salinity brine were injected into the sample. Overall, this study establishes a methodology to characterize and quantify wettability changes at the pore scale which appears to be the dominant mechanism for oil recovery by LSW.

show abstract

“…The spontaneous emulsion is also not induced by the traditional low salinity effects (improved recovery due to low invading aqueous phase salinity) described in previous studies (Du et al, 2019;Tetteh et al, 2020;Wu & Firoozabadi, 2021) in terms of occurrence, process, and consequences. For the occurrence, low salinity aqueous solutions flood did not cause emulsions or swelling before or after the polymer flood (Figure 7) but could have with traditional low salinity effects.…”

Section: Elasticity Induced Redistribution/mobilization and Salinity Related Ganglia Swellingmentioning

confidence: 71%

A Coreflood‐on‐a‐Chip Study of Viscoelasticity's Effect on Reducing Residual Saturation in Porous Media

Mejía

et al. 2021

Water Resources Research

View full text Add to dashboard Cite

Polymer aqueous solutions are widely used in nonaqueous phase liquid recovery and aquifer remediation processes due to their high viscosity. Additional reduction of residual saturation by polymer's viscoelasticity has recently been discovered which elevates the ultimate displacement efficiency. However, there is no consensus on how, and under what conditions, viscoelasticity reduces residual saturation. This is in part because most studies utilize relatively low salinity and high viscosity, which also contribute to higher recoveries. We separate the effects of viscosity, elasticity and salinity, by performing microfluidic experiments in long (30 cm) heterogeneous glass micromodels (coreflood‐on‐a‐chip). In the experiments, a highly viscous Newtonian aqueous phase flood is first performed so that the system reaches residual saturation, followed by polymer flood with varying elasticity and salinity. This is followed by another highly viscous Newtonian aqueous phase flood. We observe significant redistribution and reconnection of residual ganglia due to viscoelasticity induced instabilities during high‐viscoelasticity polymer floods, which results in residual ganglia remobilization that ultimately reduces residual saturation. In contrast, no fluid redistribution and saturation reduction are observed in low‐viscoelasticity polymer floods. During low salinity polymer floods (regardless of the relative elasticity), spontaneous emulsification occurs inside ganglia and results in ganglia swelling, which enhances ganglia reconnection when elastic instability happens, therefore amplifies the residual saturation reduction.

show abstract

Review of low salinity waterflooding in carbonate rocks: mechanisms, investigation techniques, and future directions

Cited by 115 publications

References 220 publications

Ionic Interactions at the Crude Oil–Brine–Rock Interfaces Using Different Surface Complexation Models and DLVO Theory: Application to Carbonate Wettability

Ionic Interactions at the Crude Oil–Brine–Rock Interfaces Using Different Surface Complexation Models and DLVO Theory: Application to Carbonate Wettability

Pore-scale imaging and analysis of low salinity waterflooding in a heterogeneous carbonate rock at reservoir conditions

A Coreflood‐on‐a‐Chip Study of Viscoelasticity's Effect on Reducing Residual Saturation in Porous Media

Contact Info

Product

Resources

About